US Patent 7095941 Fused optical fiber optical device system

A fused optical fiber optical device system comprises at least one optical component comprising optical fibers and at least one other optical component with which light transmitted in the optical fibers interacts, wherein the optical fiber comprises a core glass of the following composition: La2O3 1–23 mole %, ZrO2 1–10 mole %, WO3≧2.5 mole %, ZnO 1–15 mole %, BaO 0–9 mole %, B2O3 20–70 mole %, Ta2O5 0–3 mole %, CaO 0–7 mole %, PbO 6–35 mole %, SiO2 0–40 mole %, As2O3 and/or Sb2O3 0–0.1 mole %, Nb2O50–3 mole % and Al2O3 0–8 mole %. The core glass is essentially free of CdO, has a refractive index nd of at least 1.8 and a CTE of ≧about 74×10−7.